I think they're equivalent in a sense, but that bucket diagrams are still useful. A bucket can also occur when you conflate multiple causal nodes. So in the first example, the kid might not even have a conscious idea that there are three distinct causal nodes ("spelled oshun wrong", "I can't write", "I can't be a writer"), but instead treats them as a single node. If you're able to catch the flinch, introspect, and notice that there are actually three nodes, you're already a big part of the way there.

The bucket diagrams are too coarse, I think; they don't keep track of what's causing what and in what direction. That makes it harder to know what causal aliefs to inspect. And when you ask yourself questions like "what would be bad about knowing X?" you usually already get the answer in the form of a causal alief: "because then Y." So the information's already there; why not encode it in your diagram?